Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on August 4, 2009. Major professor: Dr. Helen Yu. "Presented to the faculty of California Polytechnic State University, San Luis Obispo, California." "In partial fulfillment of the requirements for the degree [of] Master of Science in Electrical Engineering." "June 2009." Includes bibliographical references (p. 49-52).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1987. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 134-137).

Data centres are an integral part of today's technology. With the growing demand for data centers to meet computational needs, there is pressure to decrease data center-related costs. By reducing the amount of power needed to cool servers, the overall power consumption can be decreased. Efficient cooling of data centres involves meeting temperature constraints while minimizing power consumption. By exploring the opportunities that may be available through controlling multiple cooling units, we can avoid issues such as overcooling (some parts of the data center being cooled more than necessary) or warm air recirculation (return of exhausted hot air to inlets of servers). Currently, in data centres with more than one cooling unit, each of the cooling units is controlled independently. This mode of operation results in each cooling unit needing to be set for the worst case, which results in over cooling and is not energy efficient. Coordinating cooling units has the potential to decrease the power consumption of a data centre by eliminating this over cooling. Furthermore, coordinating with workload management may help mitigate cooling unit power consumption. This research is concerned with exploring what is feasible within the options discussed above. It contains two main parts. In the first part, we present an algorithm to minimize power consumption of cooling units while keeping all the server cores below a temperature threshold. In the second part of this thesis, we derived a data-driven model for server outlet temperature. / Thesis / Master of Science (MSc)

Thesis (M.S.)--University of North Carolina at Wilmington, 2006. / Includes bibliographical references (leaves: [45])

This thesis is concerned with the energy efficiency of cellular networks. It studies the dominant power consumer in future cellular networks, the Long Term Evolution (LTE) radio Base Station (BS), and proposes mechanisms that enhance the BS energy efficiency by reducing its power consumption under target rate constraints. These mechanisms trade spare capacity for power saving. First, the thesis describes how much power individual components of a BS consume and what parameters affect this consumption based on third party experimental data. These individual models are joined into a component power model for an entire BS. The component model is an essential step in analysis but is too complex for many applications. It is therefore abstracted into a much simpler parameterized model to reduce its complexity. The parameterized model is further simplified into an affine model which can be applied in power minimization. Second, Power Control (PC) and Discontinuous Transmission (DTX) are identified as promising power-saving Radio Resource Management (RRM) mechanisms and applied to multi-user downlink transmission. PC reduces the power consumption of the Power Amplifier (PA) and is found to be most effective at high traffic loads. DTX mostly reduces the power consumption of the Baseband (BB) unit while interrupting transmission and is better applied in low traffic loads. Joint optimization of these two techniques is found to enable additional power-saving at medium traffic loads and to be a convex problem which can be solved efficiently. The convex problem is extended to provide a comprehensive power-saving Orthogonal Frequency Division Multiple Access (OFDMA) frame resource scheduler. The proposed scheduler is shown to reduce power consumption by 25-40% in computer simulations, depending on the traffic load. Finally, the thesis investigates the influence of interference on power consumption in a network of multiple power-saving BSs. It discusses three popular alternative distributed uncoordinated methods which align DTX mode between neighbouring BSs. To address drawbacks of these three, a fourth memory-based DTX alignment method is proposed. It decreases power consumption by up to 40% and retransmission probability by around 20%, depending on the traffic load.

Ce mémoire traite des systèmes intégrés sur puce (System-on-Chip) à faible consommation d'énergie tels que ceux qui seront utilisés dans les équipements portables de future génération (ordinateurs de poche (PDA), téléphones mobiles). S'agissant d'équipements alimentés par des batteries, la consommation énergétique est un problème critique. Ces plateformes contiendront probablement une douzaine de coeurs de processeur et une quantité importante de mémoire embarquée. Une architecture de communication optimisée sera donc nécessaire afin de les interconnecter de manière efficace. De nombreuses architectures de communication ont été proposées dans la littérature: bus partagés, bus pontés, bus segmentés et plus récemment, les réseaux intégrés (NoC). Toutefois, à l'exception des bus, la consommation d'énergie des réseaux d'interconnexion intégrés a été largement ignorée pendant longtemps. Ce n'est que très récemment que les premières études sont apparues dans ce domaine. Cette thèse présente: - Une analyse complète de l'espace de conception des architectures de communication intégrées. Sur base de cet espace de conception et d'un état de l'art détaillé, des techniques jusqu'alors inexplorées ont pu être identifiées et investiguées. - La conception d'environnements de simulation de bas et haut niveaux permettant de réaliser des comparaisons entre différentes architectures de communication en termes de consommation énergétique et de surface. - La conception et la validation d'une architecture de communication intégrée innovante basée sur le multiplexage spatial Ce dernier point a pour ambition de démontrer qu'un réseau basé sur le multiplexage spatial (SDM) constitue une alternative intéressante aux réseaux classiques principalement basés sur le multiplexage temporel dans le contexte très spécifique des architectures de communication intégrées. Nous démontrerons la validité de la solution proposée à l'aide de campagnes de simulation de haut niveau pour divers types de trafic ainsi que des simulations de plus bas niveau. L'étude concerne successivement la conception de routers SDM, des interfaces réseau et finalement d'un réseau complet. Les avantages et inconvénients d'une telle technique seront discutés en détails.

The purpose of this research was to determine if installing a smaller air compressor could reduce the electrical usage of a large semiconductor manufacturing plant. A 200 horsepower Atlas Copco compressor was installed with the existing 500 horsepower Ingersoll-Rand compressors. Testing was conducted during the regular manufacturing process at MEMC Southwest in Sherman, Texas. Analysis of the data found that installing the new compressor could reduce electrical consumption. The study also found there are specific operational setpoints that allow the compressor to operate more efficiently.

In the contemporary world, there has been a great proliferation of using smart-phone devices and broadband wireless networks, the young generation using mobile gaming market is tremendously increasing because of the enormous entertainment features. Mobile cloud gaming is a promising technology that overcome the implicit restrictions such as computational capacity and limited battery life. GamingAnywhere is an open source cloud gaming system which is used in this thesis and calculate the energy consumption of mobile device when using GamingAnywhere. The aim of the thesis is to measure the power consumption of the mobile device when the game is streamed from the GamingAnywhere server to GamingAnywhere client. Total power consumption is calculated for four resolutions by using the hardware monsoon power monitoring tool and the individual components of mobile device such as CPU, LCD and Audio power are calculated by software PowerTutor. The memory usage of the mobile device is also calculated by using Trepn Profiler application when using GamingAnywhere. Based on the obtained results, it was found that there is an increase in power consumption and memory usage of the mobile device on client side when the resolution is varying from low to high. After mapping the results of the hardware with the software, it was identified that there is very small difference between the hardware results and software results from which we could estimate that the software PowerTutor can be used instead of hardware Monsoon power tool as the software is capable of calculating the power consumption of individual components of mobile device

This report presents an implementation of the software part in a software definedradio. The radio is not entirely implemented in software and therefore there arecertain limitations on the received signal. The parts implemented are oscillator,decimation filter, carrier synchronization, time synchronization, package detection,and demodulation. Different algorithms were tested for the different partsto measure the power consumption. To understand how the number of bits usedto represent the signal affects the power consumption, the number of bits wasreduced from 20 bits to 10 bits. This reduction reduced the power consumptionfrom 2.57mW to 1.89mW. A small change in the choice of algorithms was thenmade which reduced the power consumption to 1.86mW. Then the clock rate wasreduced for some parts of the system which reduced the power consumption to1.05mW.

In just forty years, the number of mobile devices has exceeded the number of humans on Earth. With the growing computational capacity, the power demands of these devices are growing rapidly as well. Due to technological and spatial constraints, the capacity of mobile power sources has become one of the most important bottlenecks of further development. Moreover, since the power efficiency is a relatively new requirement, there are only a few tools addressing it, and the existing ones have certain drawbacks. The goal of this thesis is to design and implement a tool helping developers of Android mobile applications to identify the battery-hungry parts of application code. The proposed solution is based on a novel approach - examination of power use estimations derived from the device's state together with the information about the code that is currently being executed. The prototype implementation has been tested on two Android applications with the conclusion that the proposed approach can provide useful information to the developer, but in practice, it encounters technical limitations reducing its accuracy, and thus it can not be used as a fully automated tool for identification of battery-hungry parts of Android application code.